First stage pressure regulators mounted within air cylinder plug



March 7, 1967 E. M. SHUGARMAN 3,307,597

FIRST STAGE PRESSURE REGULATORS MOUNTED WITHIN AIR CYLINDER PLUG Filed Sept. 16, 1964 5 Sheets-Sheet 1 Z0 N0 12 SEC'O March 1967 E. M. SHUGARMAN 3,307,597

FIRST STAGE PRESSURE REGULATORS MOUNTED WITHIN AIR CYLINDER PLUG Filed Sept. 16, 1964 a Sheets-Sheet 2 i -----r/u T; l Q ia I 05 50 x i INVENTOR. 0m M s z/azmm/v ATTaQA/EK March 7, 1967 E. M. SHUGARMAN 3,307,597

FIRST STAGE PRESSURE REGULATORS MOUNTED WITHIN AIR CYLINDER PLUG Filed Sept, 16, 1964 5 Sheets-Sheet 3 Z 427 BY 2 ATTOE/VE).

United States Patent FIRST STAGE PRESSURE REGULATORS MOUNTED WITHIN AIR CYLINDER PLUG Earl M. Shugarman, Costa Mesa, Califi, assignor to W. Voit Rubber Corp., a corporation of California Filed Sept. 16, 1964, Ser. No. 396,968 7 Claims. (Cl. 141-18) This invention relates to pressure regulators for selfcontained underwater breathing apparatus.

It is an object of this invention to provide a regulator of a very compact miniaturized dimension which is mounted completely within the plug and for closing off an air cylinder which furnishes compressed air to the regulator.

It is an additional object of this invention to provide the regulator of the above type which includes a first check valve connected in series with the input-output duct which is opened by means of a push rod provided in the connector mounted at the end of a hose which is used for connecting the regulator to the second stage or to v the compressor when it is necessary to fill the cylinder with compressed air, the regulator also including a second check valve in series with the input duct and in shunt with the regulator, the second check valve being in closed position when the regulator is in operation and in open position only when the air cylinder is being filled with compressed air by the compressor.

Another object of this invention is to provide a regulator of the above type in which the regulator is made adjustable for adjusting the reduced pressure produced by the regulator on the output side.

It is an additional object of this invention to provide scuba apparatus of the above type in which the first stage regulator and the two check valves are mounted in the plug used for connecting the scuba apparatus to the neck of the air cylinder, the check valves also acting as shutoff valves in the scuba system.

Referring to the drawings,

FIGURE 1 illustrates the vertical section of the air cylinder and of the piston-type regulator and two check valves mounted within the cylinder plug;

FIGURE 2 is the vertical section of the piston-type regulator mounted within the plug and two check valves mounted on two opposite sides of the projecting portion of the plug;

FIGURE 3 is a vertical section of the piston-type regulator and two check valves mounted Within the air cylinder plug with the regulator being provided with a balancing feature;

FIGURE 4 is a vertical section of the diaphragm type regulator mounted within the cylinder plug with two check valves being mounted on two opposite sides of the plug.

Referring to FIGURE 1, the air cylinder 10 is provided with a neck 11 having an internal thread 12. A plug 13 is mounted in neck 12 by means of a thread 14. The cylinder is also provided with a dip tube 9 with a recess 8, a sintered metal filter 7, a bypass valve 6, and a duct 5. Air is supplied to the system from cylinder 10 through filter 7 and duct 5, and cylinder 10 is filled with air through duct 5 and bypass valve 6 which is a rubber band stretched over a cross-duct 4. A dip tube of this type is disclosed in William F. Summerfields patent application United States Serial Number 206,703, filed July 2, 1962, Dip Tube for Gas-Filled Cylinder, now United States Patent No. 3,148,965, granted September 15, 1964. Plug 13 is provided with an enlarged head 15 which engages -a circular wall 16 of neck 11. An 0 ring 17 is used to make an air-tight connection between the plug 13 and neck 11. Plug 13 is provided with ducts 18, 19, 20 and 21 and chambers 22, 23, 24, 25 and 32. Chamber 22 is ice connected to an ambient medium by means of duct 21 permitting the regulator to compensate for any changes in water pressure as the dive gets deeper or shallower. A first fixed plug 26 closes off the upper portion of chamber '22 and it also acts as a guide or a cylinder for a piston 27 which actuates the valve of the regulator with the aid of a push-rod 28 provided with a seat 29 for a washer 30 mounted within the seat 29. Piston 27 and push rod 28 are provided with 0 rings 39 and 31 to seal off chamber 32 from chamber 22 with O ring 39 and chamber 22 from chamber 23. Duct 18 terminates in a valve seat 33 normally engaged and closed off by washer 30. Chamber 32 is connected to chamber 23 by ducts 33 and 34 within push rod 28 and piston 27. In this manner chamber 23 is filled with air at the pressure produced by the pressure regulator. Piston 27 is subjected to a balanced pressure produced by springs 35 and 36, spring 36 being used for the sole purpose for adjusting the balanced pressure produced by the two springs on the piston. Spring 36 is held in place by means of a second adjustable plug 37 having a key recess 38 which is used for adjusting the pressure exerted on the piston 27 by spring 36 and in this manner, the reduced pressure produced by the regulator on the downstream side which includes chamber 32, ducts 19 and 20, and chambers 24 and 25. Chamber 24 is provided with a one-way check valve assembly 40 having a housing 41, a threaded duct 42, a valve seat 43, a valve 44-, a spring 45, and an adjustable cap 46, which is used for adjusting the pressure of spring 45 on valve 44. An 0 ring 47 is used to seal housing 41 within and to plug 13. An identical check valve 50 having the same elements as valve 40, is mounted in chamber 25. In this case, valve 51 normally is closed because of high and full air pressure exerted on valve 51 by the compressed air within cylinder 10. It is opened when the check valve 40 is connected to the air compressor, or a source of high pressure air, used for filling the cylinder. Air then flows into the cylinder through the two check valves 40 and 50 and duct 5. The regulator valve is now closed because of high pressure in chamber 23 which also presses on piston 27 and keeps valves 30-33 closed.

When the regulator supplies air to the second stage regulator through an outgoing hose 52, air flow-s through ducts 18, 19 and 20, periodically opened valve 30-33, chambers 32 and 24 and check valve 40. When pressure on the downstream side of the regulator valve 3033 drops because of the withdrawal of air by the second stage connected to hose 52, spring 35 opens the valve and admits air into chambers 32, 23, 24 and ducts 19 and 20 which causes valve 30-33 to close at that pressure which is capable of overcoming the pressure of spring 35 and the pressure of ambient water on the ambient side of piston 27. In this manner the regulator valve is compensated for ambient water pressure and will increase the air pressure in chamber 32 with the increase in the ambient pressure of water and vice versa.

FIGURE 2 discloses the second version of the regulator which is similar to the regulator disclosed in FIG- URE 1 except that the check valve 50 of FIGURE 1 now is externally mounted at 200. This check valve is used for (filling the cylinder 10 with compressed air through duct 201 and 202 and the dip tube 203. The second check valve 204 and a duct 205 are used for supplying air to the second stage through the hose 52 as in FIGURE 1. The second check valve is connected to a hose 206 provided at its end with a connector 207 having a push rod 208 which opens the check valve 210 when connector 207 is connected to the check valve 204.

The construction and operation of the regulator illus- 3 trated in FIGURE 2 otherwise is identical to that illustnated in FIGURE 1.

FIGURE 3 illustrates still another version of the regulator, similar to that illustrated in FIGURE 2 except that a pressure of ambient water is now introduced through a duct 3110 to compensate the regulator valve more fully for changes in the ambient pressure. For this purpose, the plug 13 is provided with a cylinder 301 and -a piston 302 forming a sliding fit within cylinder 301. Piston 3112 is an integral part of a rod 3194 which, in turn, is a part of the rod 28 and piston 27. The diameter of the piston 302 is made substantially equal to the diameter of rod 28 to obtain a complete balance.

The operation of the regulator in FIGURE 3 otherwise is similar to the operation of the regulator in FIG- URES 2 and 1.

FIGURE 4 illustrates mounting of a diaphragm type of regulator within the air cylinder plug. Plug 4% is provided with a diaphragm 401 held in place by a hollow nut 402, a spring 4113, a hollow cap 4114 provided with a hexagonal opening 4115 for adjusting the pressure of the spring on diaphragm 4111, a push rod 406 having a threaded end 407, an integral flange 4%, and the cylindrical push rod portion 4% which pushes on a rod 414) provided with a flange 424 and a poppet valve 421 molded around the upper end of a rod 419 and a flange 424. Rod 4% is fastened to the diaphragm 401 by means of the threaded end 407, a nut 411 or washer 412 and the flange 408. The poppet valve 421 and rod 410 are guided by a ring 413 inserted in a cylindrical chamber 414. The ring is provided with two rings 415 and 416 to seal off the lower chamber 417 from chamber 414. Chamber 417 is connected to a low pressure chamber 418 by a duct 419. The regulator valve includes a reversible seat 421) and the poppet valve 421 molded around rod 410 and its flange 424. A spring 422 surrounds rod 410 and counteracts the pressure of spring 4113. Spring 422 normally keeps the valve closed and seated against seat 421). The valve becomes open when diaphragm 4111 pushes down rod 4139 and rod 410 which opens the poppet valve 421. Two check valves 530 and 432 are mounted on two sides of plug 401), the check valve 430 being used for connecting the low pressure chamber 418 to the second stage in the manner illustrated in FIGURE 2 at 294, 206, 2137 and 208, while the check valve 432 is used for filling the cylinder with compressed air. A duct 425 connects the check valve 432 with a circular recess 426 and ducts 427 and 428 in a dip tube 429, the lower end of which is illustrated in FIGURE 2.

The operation of the regulator illustrated in FIGURE 4 is as follows: Cylinder 10' is filled with compressed air through the check valve 432, ducts 425, 426, 427 and 428. When the high pressure hose is disconnected from the threaded end 433 of the check valve 432, spring 434 closes the poppet valve 435 and it is also kept closed by full air pressure in cylinder 11?. The check valve 432 is provided with a sintered metal air filter 436 and a cap 437 which is used for closing the check valve 432 after the high pressure hose is disconnected. A low pressure hose 438 is connected to the check valve 430 which keeps this check valve open. When pressure in chamber 418 is low, diaphragm 4111 pushes rod 4199 down which opens valve 421. Air under pressure flows through the dip tube 429, ducts 428, 427, 417, 440, chamber 414, through the open valve to chamber 418 and hose 438 to the second stage. Duct 419 conveys low pressure to chamber 417 and balances the pressure exerted on the upper end of rod 410 by the air in the low pressure chamber 418. that 409 and rod 410 are two separate elements although they may appear as a single piece in FIGURE 4. The cross-line at the junction point 441 indicates where the two rods meet each other, rod 409 pushing on rod 410 It should be noted here when diaphragm 401 is depressed inwardly by spring 4% and ambient pressure of water.

As illustrated in all figures, an additional check valve 450 is interposed at the downstream end of the dip tube 2 and it is adjusted to a pressure in the order of ten or twenty pounds. This check valve is used for preventing water from entering the air cylinder after the air has been discharged from the cylinder. Without such check valve, the fully discharged air cylinders at times create suction and become flooded with water if under :such conditions, their necks become immersed in water. The check valve 459 interposed at the upper end of the dip tube prevents such flooding of the air cylinders.

What is claimed as new is:

1. In an underwater breathing apparatus including an air cylinder having an aperture at one end for supplying air to said apparatus, the combination comprising:

a plug mounted in the aperture of said cylinder and having a plurality of ducts located therein and an aperture extending through a side portion thereof,

a pressure regulator mounted within the plug and controlling the flow of air from the cylinder, said regulator being exposed through the plug aperture to an ambient medium to regulate the pressure of the air in accordance with the pressure of the medium,

a first check valve mounted within a first duct leading from the cylinder to the regulator said duct permitting a flow of air from the cylinder to the regulator and said regulator permitting a controlled flow of air to a second duct, and

a second check valve being positioned at the outlet of the second duct within the plug and being normally closed to a flow of air to a third duct which leads into the cylinder due to the cylinder pressure on said valve, said valve normally permitting the air to flow to a fourth duct leading to the breathing apparatus, and permitting the air to flow into said cylinder through the third duct during a filling operation when the first check valve becomes closed to a reverse flow of 2. An underwater breathing apparatus according to claim 1 wherein:

the plug includes a dip tube mounted thereto, said tube having the first duct extending axially therealong into the cylinder and the third duct intersecting the first duct at an intermediate point shunting the first check valve, said dip tube having a filter mounted at the lower end thereof and a by-pass valve for avoiding the filter during a filling operation.

3. An underwater breathing apparatus according to claim 1 wherein:

the plug includes a plurality of threaded chambers, and the first and second check valves are mounted in threaded engagement within respective first and second chambers.

4. An underwater breathing apparatus in accordance with claim 1 wherein:

the plug includes a threaded aperture at the outlet of the fourth duct and a check valve and hose assembly is mounted to the threaded aperture to feed the air in either predetermined direction.

5. An underwater breathing apparatus according to claim 1 wherein:

the pressure regulator comprises a piston-type regulator having spring means for adjusting the pressure delivered by the regulator on the downstream side of the regulator.

6. An underwater breathing apparatus in accordance with claim 1 wherein:

the pressure regulator comprises a balanced diaphragm type regulator.

7. In a pressure regulating system for a gas, the combination comprising:

a tank having an outlet portion and a pressurized chamher therein to supply the gas in controlled quantities,

a plug mounted in the outlet portion of the tank and having an aperture extending through a wall portion to an ambient medium and a plurality of ducts located therein,

a regulator mounted to the plug and including a valve portion slidably mounted within the plug, said valve portion having an enlarged head and an elongated body portion having an aperture extending axially circuit, the respective circuit portions being connected in series by said ducts, and

a second circuit for the gas comprising a third check therethrough to permit the gas to flow therethrough 10 flow of air. and exert pressure on the upper portion of the head, a plug mounted to the regulator opposite the head, first spring means mounted between the upper portion of the head and the regulator plug and second References Cited by the Examiner UNITED STATES PATENTS spring means mounted about the elongated body por- 15 2645241 7/1953 Rlede 141 18 tion to normally contact the lower portion of the 2853096 9/1958 Lee 137493 X head and urge the valve in a direction opposite the 3,211,175 10/1965 Replogle 141 18 X first spring means in conjunction with an ambient me- FOREIGN PATENTS dium surrounding said second spring means through the aperture in the plug 20 119,937 10/ 1947 Sweden.

a first supply circuit for the gas comprising a first check valve at the outlet portion of the tank, the regulator and a second check valve located at the outlet of the LAVERNE D. GEIGER, Primary Examiner.

H. BELL, Assistant Examiner. 

1. IN AN UNDERWATER BREATHING APPARATUS INCLUDING AN AIR CYLINDER HAVING AN APERTURE AT ONE END FOR SUPPLYING AIR TO SAID APPARATUS, THE COMBINATION COMPRISING: A PLUG MOUNTED IN THE APERTURE OF SAID CYLINDER AND HAVING A PLURALITY OF DUCTS LOCATED THEREIN AND AN APERTURE EXTENDING THROUGH A SIDE PORTION THEREOF, A PRESSURE REGULATOR MOUNTED WITHIN THE PLUG AND CONTROLLING THE FLOW OF AIR FROM THE CYLINDER, SAID REGULATOR BEING EXPOSED THROUGH THE PLUG APERTURE TO AN AMBIENT MEDIUM TO REGULATE THE PRESSURE OF THE AIR IN ACCORDANCE WITH THE PRESSURE OF THE MEDIUM, A FIRST CHECK VALVE MOUNTED WITHIN A FIRST DUCT LEADING FROM THE CYLINDER TO THE REGULATOR SAID DUCT PERMITTING A FLOW OF AIR FROM THE CYLINDER TO THE REGULATOR AND SAID REGULATOR PERMITTING A CONTROLLED FLOW OF AIR TO A SECOND DUCT, AND A SECOND CHECK VALVE BEING POSITIONED AT THE OUTLET OF THE SECOND DUCT WITHIN THE PLUG AND BEING NORMALLY CLOSED TO A FLOW OF AIR TO A THIRD DUCT WHICH LEADS INTO THE CYLINDER DUE TO THE CYLINDER PRESSURE ON SAID VALVE, SAID VALVE NORMALLY PERMITTING THE AIR TO FLOW TO A 